The invention relates to optics, specifically to prisms.
The use of prisms for the refracting of beams in one dimension is well established in the art. A beam transmitted into a prism through a perpendicular face and refracted out of the prism through an angular face is reduced in width. Prismatic beams are afocal, and this means that a beam can be refracted and reduced in width several times. This is illustrated in Sanagi's Luminous Flux Apparatus Using Prisms, Japan Pat. No. 119,260.